Help a shooter with your expertise

Are releases/permission for filming the general public at a trade show in Germany needed?

Hello everyone! I wonder if anyone can help provide advice on releases/permissions?

I'm going to be shooting some corporate content at a trade show next week in Germany. Normally we would only acquire a signed release form from anyone who is featured or a focal point in our footage, however our clients insist there has been a change to EU law that says regardless of people being featured or a focal point, we still need permission to use footage with the public in it. We want to shoot the event as a whole and show the buzz of it for example so people passing in and out of frame wouldn't be featured but may still be visible. Does anyone know anything further about the permissions required for this sort of thing?